these 2 derivations will be built:
  /nix/store/9xn7dk8hv5n9kzdnaj4ywz2n5f85ak32-cargo-vendor-dir.drv
  /nix/store/irk1p7d6py6xbijcbh7i5ymcki9ama0v-horae-tests-0.1.0.drv